Motor control.



No. 863,188. PATENTED AUG.13, 1907.

G. B. LARZELERE. MOTOR CONTROL.

APPLIOATION FILED JAN. 16, 1907.

3 SHEETSSHEET 1.

IW [M I WM .9. I

Q l l l l l l' WiLnesses: r Inventor v Charles B.Lar'zelere,

No. 863,188. PATENTED AUG. 13, 1907.

c. B. LARZELERE.

MOTOR CONTROL.

APPLICATION FILED JAN. 16, 1907.

3 SHEETS-SHEET 2.

No. 863,188. PATENTED-Afifm, 1907.

- 0. B. LARZELERE. MOTOR CONTROL.

APPLIUATION FILED JAN; 16, 1907.

' 3 SHEETS-SHEET 3.

Witnesses: \nvenbof Charles BLarzzlere,

.circuit. H motor by a resistance, then disconnect a half-field oi'ne'ct'ed half-fields in parallel with the resistances, and

UNITED STATES CHARLES B. LARZE'LERE, or sonnnnoranvrivnvv COMPANY, AooRPonaTIO or NEW YORK.

PATENT OrFIoE.

YORK, ASSIGNOR TO MOTOR CONTROL.

To gill whom it may concern:

Be it known that I, OHARLESB. LARZELERE, a citizen of the UnitedStates,'residing at Schenectady,

series to parallel withoutopening the motor circuit,

and without unbalancing the load on the two motors. My invention thusparticularly adapted to the control of electric automobiles, since insuch machines it is desirable-that the torque should'be' maintained.

during speed changes and driving motors, so as to prevent skidding. I

In passing from series to parallel position in accordance with myinvention, I provide the motors with divided field windings and firstconnect the halves of each'motor field in parallel with each other. Thisshould remain equal on-both connection has been employed heretofore forthe purpose of securing an'intermediate speed Without the use ofresistances.

My' invention consists in the method of shifting the motors from this sparallel, to parallel connection of the motors with halffields ;in'series. I accomplish this by disconnecting a half-field of each motor,and utilizing it to establish parallel connection Withoutinterruptingthe motor More specifically stated, I first shunt each eachmotor, andbreak the series connection between the motors; leaving eachmotor connected to the source.

in series'with resistance. Then I connect the disconthen break thecircuits of the resistances. The motors are thus left connected inparallel Witheach other to the sourceof voltage, with no resistance icircuit and with the half-fields of each 'motor in series. Thetransition is made without opening the'motor circuit andwithoutunbalancingi the torques of the motors. My invention will bestunderstood by reference to the. accompanying drawings, in which Figure 1shows diagrammatically a' pairof motors provided with the controllingswitch arranged to conbrol the motors in accordance with myinvention;and Figs. 2 to 20, inclusive, how the connections estabished .by thecontrolling 'erent positions. V t

In the drawingsA and Arepresent the armatures \f two serieswoundmotors,- each of which has its field livided'in half. The half-fields ofmotor'A are indirated by F and F fand the half-fields of motor A byP-and F Specification of Letters Patent. Application filed January 16,1907.

dotted lines a, b, c and d,.a'nd two reverse to the control ofseries-wound eries connection, with half-fields in c'uiting of field Fas shown in Fig. 5.

p This is shown in Fig. 9. A switch of Fig.-

in its dif- Serial lie-352,535-

B represents the source of current for the motors, which I have shown asa battery. R and R"represent resistances. i

S. is a'c Ontrolling switch having contact-fingers 1 to 14, four forwardrunning positions indicated by the positions indicated by the dottedlines a and b i When controlling switch S is moved into its first for-GENERAL ELECTRIC memes Aug. 13,1907. I

Ward running position, indicated by the dotted line a,

armature A is connected to one terminal of field F through fingers l and2; field F is connected to field F through fingers 4 and 3 field F isconnected tofie-ld field F through fingers 12 and I1; and field F isconnected' through armatureA through fingers 1.3 and 14. Theseconnections are shown in Fig. 2.. In this position of the'sw'itchthemotors are connected in series When switch S is moved from position atoward position b, the first change that occurs is the sho'rt-circuitingof field F through fingers 4 and 5, andthe short-cirthrough fingers land 11. This connection is shown in Fig. 4. The circuits of fields F andF are then opened at contact-fingers3 and 12,

nected in parallel with the half-fields F and F respectively, as shownin Fig. 6. This" figure represents.

.F through fingers and field F is connectedto In Fig; 2, the resistancesR and 'RRarO These half-fields are then c onthe connections establishedinposition'b of switch S.

-'In this positionthe motors are in series with thehalffield's of eachmotor in parallel. Fig. 7 is the same as Fig. -6, with the resistance Ran'dR added.

When the switch is moved from position b, the lefthand terminal ofresistance R is connected to thelcfthand terminal of batterythrough'fingers 8.and'9,

and the right-hand terminal of resistance R is connected to the righthand terminal of battery B through fingers 6 and 7. The connectionsshown in Fig. 8 are thereby established, and it will be seen that aresistance parallel with each motor. As the is connected in movementoi-the switch continues, the circuit of halffield F is broken at bothfinger 3 and finger 5, and the circuit -of.half-field F is broken atfingers 12 and.].0. further movement of the switch connectseachhalf'efield in parallel to aresistv ance, as shown in Fig. 10 Thehalf-field 'Fis connected in 'parallel to the resistance 3 and thehalffield F in parallel to the resistance R. A further movement of theswitch breaks the circuits of thetwo resistancesat fingers 7 and 8,-leaving the connections shown in Fig. 11 corresponding to position 0 ofswitch.

' will be noted that the motors.

oi the switch, and Fig. 20, the connections in position b.

S. In this figure, the twomotors are connected in parallel, with thehalf-fields of each motor in series. It transitionirorn Fig. (i to Fig.11, has been made without breaking the motor circuit, and withoutunbalancing the load on the two motors.

Fig. 12 is the same as Fig. 11, with the resistances added. In Fig. 13,however, fields F and F are again short-circuited then open-circuited asshown in Fig. 14, and thenconnected in parallel with the half-fieldsFond F, as shown in Fig. 15. The connections shown this figure are thoseestablished in position 11 of switch S. The motors are now in parallel,with the half-fields of each motor in parallel. Fig. 16 is the same to20 show the connections established in the reversepositions of theswitch S. These figures correspond to Figs. 2, 4. 5 and 6, except thatthe field connections are reversed to reverse the direction of rotationof the Fig. 17 shows the connections in position a What I claim as newand desire to secure by Letters Patent of the United States, is,-

l. The method of shifting a pair of series motors with divided fieldwindings from s ries to parallel connection. which consists in firstconnecting the halves of each field in parallel to each other. thendisconnecting a half-field of each motor and employing these half-fieldsto connect each motor directly to the. source without opening the movtorcircuit.

2. The method of shifting a pair of series motors with divided fieldwindings from series connection of the motors with half-fields of eachmotor in parallel toparallel connection oi the motors with halt-fieldsin series, which conas Fig. 15, with the resistances added. Figs. 17

sists-in shunting each motor by a resistance, then shunting eachresistance by half-field, and then breaking the circuiis ol' theresistances.

ii. The method of shitting a pair of series lnotors with divided lieldwindings from series connection of the motors. \vilh halt-fields of eachmotor in parallel to parallel con necliou with half-fields in series.which consists in shunting each motor by a resistance. breaking theseries connection between themotors and the circuit of one half-,

field of each motor onnecting said half-fields in parallel with theresistances. and breaking the circuits of said re sistunces.

-l. ln combination, a pair of series motors each having,

-its field divided in half and proyided with terminal leads or eachhalt-field. and a controlling switch connected to said leads and rangedin one position to connect the motors in series with the half-fields ofeach motor in parallel and by its movement to another position todisconnect a half-field 01' each motor'nnd connect the motors inparallel, with the halt-fields of each motor in series, without breakingthe motor circuit.

In combination, a pair of motors each having its field divided inhaltand provided with terminal leads for each half-field. and a controllingswitch connected to said leads and arranged in one position to connectthe motors in series. with the half-fields 0! each motor in parallel,and by its movement to another position to shunt each motor by aresistance. then to break the series connection of the motors and todisconnect a halt-field of each motor and connect it in shunt to one. ofthe resistances, and then to open the circuits of the resistances.

in witness whereof. I have hereunto set my hand this 15th day ofJanuary, 1907.

CHARLES B. LARZELERE.

Witnesses BnXJAnLN B. HULL, lI nmcx Onion).

